// A host paragraph to hold the example Inline elements..
Paragraph par = new Paragraph();

// Some arbitrary Inline elements.
Run run1 = new Run("Text run number 1.");
Run run2 = new Run("Text run number 2.");
Bold bold = new Bold(new Run("Bold text."));
Italic ital = new Italic(new Run("Italic text."));
Span span1 = new Span(new Run("Span number 1"));
Span span2 = new Span(new Run("Span number 2"));

// Add the Inline elements to the Paragraph. Note the order
// of the inline elements in the paragraph; the order is 
// arbitrary, but the notion of an order is important with 
// respect to  what are 'previous' and 'next' elements.
par.Inlines.Add(run1);
par.Inlines.Add(run2);
par.Inlines.Add(bold);
par.Inlines.Add(ital);
par.Inlines.Add(span1);
par.Inlines.Add(span2);

// After this line executes, "previousSibling" is null, since "run1" is
// the first Inline element in the Paragraph.
Inline previousSibling = run1.PreviousInline;

// After this line executes, "previousSibling" holds "bold", which is the
// first peer-level Inline preceeding "ital".
previousSibling = ital.PreviousInline;

// After this line executes, "previousSibling" holds "span1", which is the
// first peer-level Inline preceeding "span1".
previousSibling = span2.NextInline;